1. Field of the Invention
The present invention relates to an apparatus and a method for visualizing the relationship between the posture or the shape of the human body and evaluation indexes thereof, and a method for improving the posture.
2. Description of the Related Art
Utilizing the posture of the human body at the time of rehabilitation aimed at functional recovery or physical exercises for health maintenance in order to evaluate the rehabilitation or the physical exercises has been attracting greater attention. As an index for evaluating the posture, the center-of-gravity line (the line extending upward in the vertical direction from the center of gravity), which can be obtained by measurement of the human body, the positional relationship between the center-of-gravity line and the respective parts of the human body such as the knees or the waist (hereinafter referred to as a “human body part”), or the like is used.
For example, whether a person is standing in a stable posture can be evaluated according to the unstableness of the center-of-gravity line. Whether a person is able to walk in a safe posture can be determined according to whether the center-of-gravity line is on the foot on the rear side. Also, if the center-of-gravity line is in front of the rear-side foot, the human body will fall if the front-side foot slips. The distortion in posture can be evaluated according to the amount of deviation of the central position of a human body part such as the knees or the waist from the center-of-gravity line. However, it is difficult for the person who is performing rehabilitation or physical exercises to understand and realize such indexes during rehabilitation or physical exercise.
Therefore, in order to enable the person to understand the indexes for himself or herself, a technique is known in which an index that evaluates the posture of a person based on the human body measurement results is displayed superposed on the video image of the person captured by a camera. For example, Japanese Patent No. 3721330 (hereinafter referred to as “Document 1”) discloses attaching a means for detecting the position of the center of gravity of a patient to a supporting means for supporting the patient when an x-ray image is captured. Document 1 discloses a technique in which the center-of-gravity line obtained based on the detected position of the center of gravity is displayed superposed on the x-ray image. With this technique, since the relationship between the center-of-gravity line and the posture shown in the x-ray skeleton image is expressed visually, it is easy to understand the relationship.
Also, Japanese Patent Laid-Open No. 2005-224452 (hereinafter referred to as “Document 2”) discloses a technique for making a diagnosis on the posture using the center-of-gravity line and the video image of a person captured by a camera. With this technique, the diagnosis is made on the posture based on the relationship between the center-of-gravity line calculated based on foot pressure meter values, and the coordinates of the posture diagnosis point of the person in the video image. By this method, although it is difficult for a person to understand the index and evaluate his or her posture for himself or herself, it is possible to obtain an evaluation of the posture based on the index.
However, in a technique such as that disclosed in Document 1, the posture and the evaluation index thereof are simultaneously expressed on an x-ray skeleton image. Accordingly, it is difficult for people who are not doctors or physical therapists to correctly interpret the relationship between the displayed posture and the evaluation index thereof. Also, for lay people, although an ultimate evaluation result of the posture can be obtained with a technique such as that disclosed in Document 2, it is difficult to understand the evaluation result. Consequently, lay people cannot know how to improve their postures without hearing an explanation about the evaluation result.